The present invention relates to folded sheet materials, regardless of whether in the folded or unfolded condition.
It is known to fold maps with a first set of vertical concertina folds (which term means that the folds are alternately towards and away from the front of the sheet) and, once the map is folded, to impose a second set of folds (not concertina) that are horizontal. It is further known for such a map to have a stiffening portion which extends over the whole of one corner segment produced by the folds and beyond this for a similar area outside the map so that when the map has been folded completely the outside stiffened portion can be folded over the map so that the map is wholly contained between the two parts of the stiffened portion that are hinged together.
It is known, for instance from U.S. Pat. No 5,156,898 to provide a sheet of paper or like material having a first and a second set of concertina folds with the second set of folds being transverse to the first set when the sheet is folded. The sheet is provided with two stiff portions at diagonally opposite corner segments of the sheet, so that the sheet can be unfolded with a single movement and possibly using only one hand to grasp and unfold the sheet.
For the purposes of the ensuing description and claims, xe2x80x9csheet materialxe2x80x9d is hereby defined as a sheet material which has folds in it, regardless of whether it is in a folded condition or not unless the context otherwise requires, and further is a material that takes folds at which it can easily be unfolded (without the folds disappearing) and refolded. It may be paper, or a paper-like material such as plastics sheet on which books are commonly printed, or may be very thin card or any other suitable flexible material. It is conceivable that the sheet material may be stiff except at the folds, e.g. very thin cards interconnected by paper or cloth, but this is deprecated as not allowing full realisation of the advantages of the invention.
The present invention provides a sheet material having a first set of folds the sheet material further comprising a rotatable disc attached thereto.
Suitably, the sheet material is provided with a stiff portion at a segment thereof. Suitably, the segment at which the stiff portion is provided is at a corner of the sheet and is defined by fold(s) and/or edge(s) of the sheet.
Suitably, the first set of folds is concertina folds.
Suitably, the rotatable disc is attached to the stiff portion of the sheet means. Suitably, the rotatable disc is located on the exterior surface of the stiff portion when the sheet is in the folded condition.
Suitably, the stiff portion to which the rotatable disc is attached has a cut-out section which facilitates rotation of the disc.
Suitably, the disc comprises one or more cut-out sections or slots, such that information given on the stiff portion may be selectively viewed through the cut-out section(s) or slots. Alternatively, the disc may comprise selectively translucent, preferably transparent, sections for the same purpose.
Suitably, the disc comprises cardboard material, plastics material or a combination thereof. The plastics material suitably comprises opaque and transparent sections, although it may additionally or alternatively comprise cut-out slots. The disc may further comprise markings on the surface thereof.
Suitably, the disc is a substantially flat disc. The disc may comprise a projection on the surface thereof, which projection helps or provides for rotation of the disc.
Suitably, the disc is connected to the sheet material at the centre of the disc by attachment means. Suitably, the disc rotates about the attachment means. The attachment means may comprise a pin or rivet, for example.
The disc may have any shape, such as circular, elliptical, square or rectangular, but is preferably circular.
The sheet material may comprise only a first set of folds.
Suitably, the sheet material comprises a second set of folds, which second set of folds may comprise a single fold. Suitably, the second set of folds is a set of concertina folds. Suitably, the second set of folds are arranged so as to be transverse to the first set of concertina folds.
Suitably, the sheet material further comprises a second stiff portion located at a segment of the sheet, which segment is defined by edge(s) and/or fold(s) of the sheet. Preferably, the segments at which the first and second stiff portions are located are at or near diagonally opposite corners of the sheet. This enables the sheet material to be unfolded in a single movement in which one hand grasps one of the stiff portions and the other hand pulls the other stiff portion away from the first one.
Although one or both sets of folds may be non-parallel, e.g. convergent, and/or one or both of the stiff portions may, when the sheet is properly folded, not be outer portions, in a preferred embodiment the sheet is rectangular, the sets of folds being mutually perpendicular and parallel to the respective edges of the sheet, and the stiff portions being such as to be at the outside of the sheet when it has been folded by the first set of folds and then by the second set of folds and being at least as large as the respective segments of the sheet.
In this case, and particularly if the first set consists of an odd number of folds and the second set consists of an even number of folds, one hand can grasp the back stiff portion whilst the other hand can grasp the front stiff portion and pull it downwards and then sideways turning it over, so as to open the sheet with what in practice amounts to a single movement, assuming the sheet to be flexible at and near the folds.
By experiment, the most suitable folding for this action has been found to comprise five folds in the first set and two folds in the second set. Furthermore, if the stiff portions are slightly larger than the respective corner segments of the sheet it is easier to grasp the stiff portions.
Also, it is relatively simple to reverse the action and fold up the sheet again with a single movement. If this facility is then combined with the stiff portions being provided with holding means adapted to hold the portions together to keep the sheet folded, a particularly convenient embodiment is provided, one which can be rapidly unfolded and rapidly refolded and kept in position without undue fiddling. The holding means may comprise oppositely magnetised parts of the respective stiff portions or (though this has not been found so effective) may comprise hooked material and looped material at the respective stiff portions.
The invention is particularly suited to printed sheet material intended to be carried around in the pocket (e.g. for the uses indicated below) for which purpose the folds may divide the material into segments about 4 to 8 cm in width by about 6 to 12 cm in length. It is preferred that the whole package should be roughly the size of a credit card, i.e. with folds dividing the sheet rectangularly into segments of about 5 to 5xc2xd cm width by about 8 to 8xc2xd cm length.
In a preferred embodiment, the material (apart from the stiff portions) is paper or paper-like material (e.g. of plastics) and the stiff portions are of semi-rigid material, principally of plastics (e.g. apart from magnetisable material for the purpose mentioned above), attached to the remainder of the material.
An embodiment which has particular uses in awkward situations is produced if at least one of the said diagonally opposite stiff portions (usually the front one) is sufficiently massive to allow a single-handed holding and opening of the sheet. In this case, the back stiff portion is held in one hand with the massive front portion resting lightly on the remainder of the folded material and then this is jerked so that the massive front portion flies away from the grasped back portion, thus automatically enabling the sheet to be held and opened, both with one hand.